1. Field of the Invention
The invention relates to assays and more particular to sensors for use with assays.
2. Background of the Invention
A variety of assays can be performed using an assay chip that includes one or more sensors positioned on a substrate. Each of the sensors can include a working electrode, a reference electrode, and a counter electrode positioned on the substrate. The reference electrode typically includes or consists of two metal layers that contact each other so the reference electrode has an intrinsic potential against which the potential of other electrodes can be measured.
In some instances, the reference electrode is made with a single layer of metal in order to reduce challenges associated with manufacturing the reference electrode. However, these sensors are often produce inconsistent results because the potential of the reference electrode can float. As a result, there is a need for a manufacturable sensor that can provide consistent results.